Carburetor



July 14, 1925. I v 1,545,483

M G. CHANDLER CARBURETOR Fild'Feb. 21, 1921 2 Sheets-Sheet 1 Jul 14, 1925. 1,545,483

M. G. CHANDLER CARBURETOR Filed Feb. 21, 1921 2 Sheets-Sheet 2 E E I Patented July 14, 1925.

"um'ran s'ra'ras 1,545,483 PATENT err-ice.

MILFORD G. QHANDLEB, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNEASSIGNMENTS, '10 CURTIS B. CAMP, TRUSTEE, 02 OAK IABK, ILLINOIS.

cannons-ran.

Application filed February 21, 1921. Serial No. 448,774.

To alt whom it may. concern:

Be it known that I, MILFORD G. CHANDLER, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Carburetors, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings forming a part of this specification.

My invention relates to improvements in carburetors of that type known as suction feed carburetors, wherein fuel is lifted from a low level fuel supply tank by the suction produced in the intake manifold of the em gine to which the carburetor supplies fuel.

The primary object of the invention resides in the provision of a suction feed carburetor having the power, or substantially the same power as a standard gravity feed carburetor, notwithstanding the fact that suction in the intake manifold of the engine is utilized continuously to lift the fuel from the low level fuel supply tank to the carburetor.

A second object of the invention is the provision of a carburetor having the characteristics above outlined and in which certain novel parts and the arrangement thereof render the device susceptible of production in large quantities and usable with a variety of different forms of intake mamfolds. I i

The carburetor consists of a fuel chamber which is supplied with fuel from the low level supply tank. The fuel chamber communicates with and is adapted to eject its fuel into a fuel nozzle having communication with the carburetor mixing chamber. The intake manifold suction is utilized to create a vacuum in the fuel chamber for liftin the fuel. The suction in the intake manifo d, if maintained high enough to lift the fuel of itself, would result in a loss of power in the r operation of the engine at such times as the ultimate power is desirexl, such as when climbing hills, accelerating, and driving through sand or mud at comparatively low speed and with wide open or nearly wide open throttle. At such times, any restriction suitable for causing a static vacuum in the intake manifold decreases the engine power in a somewhat definite relation to the degree of restriction to the inflo'wing air or mixture. In order to utilize the intake .higher suction in the fuel chamber than manifold suction for lifting the fuel-and at the same time maintain this suction at a point consistent with efficient engine operation, I provide suction boosting means to create a higher degree of suction than that in the intake manifold or in the mixing chamber of the carburetor, and utilize this greater suction in the fuel chamber to ele vate the fuel. The suction boosting means comprises a small Venturi tube, the inner end of which is subject to the suction of the intake manifold and the outer end thereof to atmosphere. 'In this manner' a suction greater than that at the inner end of the Venturi tube is formed at its throat. This suctionis used for elevating the fuel. The

fuel nozzle must besubject to a greater. suction than obtains in the fuel chamber, in order that fuel may be fed, and to accomplish this I utilize a nozzle of Venturi shape constructed somewhat similarly to thefirst mentioned Venturi, but which has a greater suction increasing effect than the first.- In this way the required pressure differential between the nozzle and the fuel chamber is maintained to secure proper fuel feed.

I have found that when there is an increased flow of air through the mixing chamber, it is necessary to produce a slightly would be produced by the suction acting upon the inner end of the suction Venturi tube, and to accomplish this I provide novel means connected with the anterior air valve for regulating the, increased suction obtained from the small Venturi. v

The foregoing .and other objects will appear from the following detailed description taken in connection with the accompanying drawings, wherein Figure 1 is a vertical-cross section of the carburetor;

Figure 2 is a horizontal section taken on line 2-2 of Figure 1; and

Figure 3 is a vertical sectional detail taken along the line 3-3 of Figures 1 and 2, looking in the directions indicated by the arrows.

The same characters of re erence refer to the same parts throughout the several views.

Referring firstto Figure 1, the carburetor of my invention is ma e up of three castings 6, 7 and 8. The casting 6 will hereinafter be referred to as the main casting, and con tains an air passageway 9 extending therethrough, the lower end'of the passageway being enlarged at 10. Themain casting 6 has the usual flanges 11, 11, for attaching the carburetor to an engine manifold. Fitting in the passageway 9 and held in place by a set screw 12 is a large venturi 13 provided at its throat or at a point slightly posterior to its throat with a duct 14 com municating with a similar duct15 formed in the casting 6 and communicating with the upper end of a cylinder 16. Slidably mounted in the cylinder 16 is a loosely fitting piston 17 carrying a tubular extension 18, in turn co-operatingwith a guide pin 19 for the purpose of guiding the piston 17in its The guide pin 19 is rigidly held in the'cast ing 6 in any convenient manner, as for example by' means of the pin shown at 20, which extends through the casting and through the guide pin 19: A helical com- "PIGSSIOII spring 21 is interposed between the main casting and the piston 17 to hold the p ston normally in the position shown in Fugure 1. A rotary valve 22 extends across the duct 15. This valve has a duct arranged to register with the duct 15*, as shown. The

valve 22 carries any suitable operating lever for operating it strument board.

Extending across the enlarged portion 10 from the automobile inof the passageway 9 is a spider 23threaded at 24 to receive a venturi shaped nozzle 25. The lower central end of the spider 23 is made tubular, as shown at 26, to form a portion of the primary air intake passageway.

The Venturi nozzle 25 is shaped as most clearly shown in Figure 3,1with a step or suddenly enlarged part 27 slightly posterior to the throat thereof, at which point the several fuel feed openings 28 are formed. The openings 28 communicate with the annular chamber 29 formed between the nozzle and the spider 23. A fuel supply duct 30,-

registering' with asimilar duct 31 formed in the float chamber casting 8, provides communication between the float chamber and the annular chamber 29. 7

The specific form of float chamber and float mechanism is unimportant and has no bearing on this invention. It is, however,

necessary, as will laterappear, to provide a cover for the float chamber which has an air-tight fit.

A fuel feed duct 32 extends vertically through the float chamber casting 8 and communicates with -the feed duct 31 and with the lower end of the fuel chamber. A metering pin 33 is threaded through the float chamber cover and serves as a means whereby the passagenof fuel through the duct 32 may be regulated. i

The float chamber casting 8 is secured to the main casting 6 by a air of screws 34-34. These screws are msertable from movement within the cylinder.

the interior on the float chamber and have screw-threaded engagement with the main casting 6. The main casting 6 has four holes shown at 35 for receiving the screws 34, sothat the float chamber may be rotated about theaxis assing through the duct 31 into any one of four positions with respect to the main casting. This construction makes it possible to use the same carburetor I for either vertical or horizontal application to the manifold, and even permits the carburetor to be mounted to discharge downwardly into the manifold when desired.

Formed in the, casting 8 of the fuel chamber and concentric with the duct 31 is an annular passageway 36 having communication with the chamber directly beneath its cover through the duct 37 (Figure) 1)- The annular passageway 36 also has communication with a duct 38 formed in the main casting which communicates with the annular chamber 39 formed between the small venturi 40 and the main casting. This last mentioned chamber communicates in turn with one or more apertures 41 located prefwardly through the airpassageway 10 provided in the main casting. The venturi lies in a bushing 42, the outer flanged end of which is provided with a ca-mmed'surface 43. A pin 44 on the lever 45 engages the surface 43 and causes movement of the venturi outwardly when the same is rotated by means ofi the lever 45 -which may be operated .in any convenient manner from the instrument board of the automobile. A leaf spring 46 carried by the post 47 is arranged normally to hold the venturi in its adjusted position.

Attached to the main casting 6 by two screws 48-48 is the air born casting 7,

containing the two passageways 49 and 50,

the former communicating with the passageway 9 of the main casting and the latter constituting a primary air intake communicating with the passageway 26 formed in the spider 23.

Mounted on the-shaft 51 and within the secondary air passageway 49 is an anterior air valve 52 carrying a lug 53 which is attached by means of the cotter pin 54 with a link 55. The opposite end of the link is connected by the cotter pin 56 with a projection extending outwardly from the piston 17, the link and said projection extending through an opening 57 formed on the upKerface of the horn.

boss 58 is formed on the inner side of the valve 52. The boss is'provided with a socket to receive the enlarged rounded end of a link 59 which has a'pivotal connection at its opposite end with a frame 60.

i The frame 60, as most clearl shown in cylinder. An increased engine speed is se- Figure 2, is curved to lie aroun one side of cured by opening the throttle 64% the des red the tubular cast portion of the air horn which provides sageway 50. post 61 is threaded into the air born casting 7 adjacent and parallel to the tubular cast portion just mentioned and is enlarged to provide a shoulder at 62. The post 61 serves as the mounting for the frame 60, which engages the shoulder 62. A cam 63 is carriedupon the-frame 60 and lies in spaced relation to the posterior end of the small venturi 40. As most clearly shown in Figure 2, the cam is contoured so as to provide various clearances with the venturi to properly proportion the amount of air passing through the venturi at dificrent engine speeds. Opening of the valve 52 to permit] influx of air through the auxiliary air passage-way 49 causes movement of the cam 63 to vary the clearance just mentioned.

A throttle 64 located in themixing chamher 9 is arranged. to control the passage of air therethrough. I

The operation of the device is as follows:

Assuming that the carburetor issecured upon the intake manifold ofan engine and that the engine is operating withthe throttle 6t partly open, a suction is produced in the mixing chamber 9, with the result i is greater than that fuel is drawn'through the duct 30 and through the openings 28 into the mixing chamber. The reduction ofpressure in the mixing chamber 9 causes air to be drawn in through the small venturi 40. The posterior end of the venturi 40 being subject to the suction of the mixing chamber 9 and the anterior end thereof being subject to atmosphere, a reduction in pressure is created at the throat of the venturi 40 which that existing at the instant in the mixing chamber 9. This enhanced suction is comnmnicated to the upper portion of the float chamber and serves to elevate fuel from a low level fuel reservoir to the fioat "chamber. The suction of the mix ing chamber 9 is also communicated tov the cylinder. 16 above the piston 17 therein through the registering ducts 14 and 15. The lower side of the piston 17 is subject to atmosphere through opening 57 so that the piston is caused to move upwardly in the cylinder 16 against the tension of the spring 21. The anterior airi valve 52, in consequence of the upward movement of piston 17 is opened an amount corresponding to the suction produced in the cylinder 16.

The amount of suction produced in the cylinder 16 may be regulated to the desired extent by manipulating the rotary valve 22; the fit of the piston 17 in thecylinder being suficiently loose that a small amount of air leaks around it so that variations in the size of the opening affect the suction in the the primary air inlet paswhereby the carburetor through the mixing chamber 9. This increased flow of air would cause a proportionately increased flow of air through the venturi 10. In order to maintain a proper pressure differential for delivering properly-proportioned quantities of fuel and air, the cam-63 is provided and is arranged to be operated in unison with the valve 52. The. shape or contour of the cam is determined entirely experimentally.

Thus, a cam having a roughly approximated contour is used as a basis for this experimental determination and placed in the carburetor. This experimental cam is then tried for various engine speeds. If the mixture is found to be too rich at some given engine demand," for example; the coil: tour of this experimental cam is filed down at the point whioh at that particular engine' demand comes opposite the end of the venturi 10, in order to permit a greater quantity of air to pass in through the venturi- 40 to cause a greater suction on the surface of the fuel in the float chamber and thereby cause a consequent'decrease in the fuel feeding differential at the nozzle. The

what I claim as new and desireto secure by Letters Patent of the United States is 1. A carburetor comprising "a casing provided with'an air passageway extending therethrough, a fuel nozzle in the passage way, a second casing forming a float chainber, means for attaching the second casing to the first in either one of two positions, may be converted from a horizontal to a vertical type, and means whereby communication is had be tween the fuel nozzle and-the lower part of the fuel chamber and between the air passageway and the upper part of the fuel chamber, for both positions of the fluid chamber.

2. A carburetor comprising two separate castings, one of which contains an air passageway forming a. mixing chamber and the other a reservoir formin a float chamher, a fuel nozzle in the mixing chamber, a screw insertable from the inside of the float chamber for connecting the two castings in loo either one of two positions, in one of =which the axes of the float chamber and mixing chamber are parallel and in the other the axes are at right angles, said fuel nozzle having communication with the lower part of the float chamber, the upper part'of the float chamber having a suction connection valve in said auxiliary air passagewayand,

with the airpassageway, and means whereby said communications are maintained when the castings are connected in either one of the two positions set forth.

3. A carburetor comprising a casing provided withan air passageway, a cylinder communicating with said passageway sub ject to the pressure existing therein, a valve between said assageway and said cylinder to regulate tie pressure communicated to the latter, an air horuhaving a primary and an auxiliary air passageway communicating with said first-mentioned air passageway, a piston movable in said cylinder, said piston being subject on one side to the pressure in the cylinder, and on the opposite side to atmosphere, an anterior air connected with said piston to be operated thereby, a venturi extending into said air passageway subject at its posterior end to the reduction of pressure in said passage way and at its anterior end to atmosphere to produce at its throat "an enhanced suction for elevating fuel from a low level reservoir to the carburetor and means operable by said anterior valve for controlling the amount of air passing through said ventur'i to regulate the suction produced thereby.

4. A carburetor comprising a casing having an air passage-Way, a fuel chamber, a nozzle venturi subject to the reduction in pressure produced in said air passageway and having communication with said fuel chamber at its throat to cause a flow of fuel from said fuel chamber thereto, a small venturi'having its posterior end subject to the .reduction in pressure produced in said air passageway and its anterior end to atmosphere to produce at its throat an enhanced suction for elevating fuel from a lower level to the level of the carburetor, the throat of said small venturi having communication with the upper portion of said fuel chamber, the suction of said small venturi and that of said nozzle venturi creating a pressure dilierential between said fuel chamber and the throat of said nozzle venturi which governs the amount of fuel delivered; to the latter, an air valve for controlling the ssage of air through said passageway, an means connected therewith to be moved thereby to regulate the action of said small venturl thereby to control the said pressure differential to alter the proportion of fuel delivered wit-h the amount of air passing through said passageway.

In witness whereof, I hereunto subscribe my name this 17th day of February, 1921.

MILFORD CHANDLER.

Witnesses:

EDNA V. GUSTAFSON, E. J. BUURGEOIS. 

